<template>
  <div class="list" ref="wrapper">
    <div>
      <div class="area">
        <div class="title border-topbottom">当前城市</div>
        <div class="button-list">
          <div class="button-wrapper">
            <!-- this.$store.state.city  获取公共数据store下的state里的city -->
            <div class="button">{{this.currentCity}}</div>
          </div>
        </div>
      </div>
      <div class="area">
        <div class="title border-topbottom">热门城市</div>
        <div class="button-list">
          <div class="button-wrapper" v-for="item of hot" :key="item.id" @click="handleCityClick(item.name)">
            <div class="button">{{item.name}}</div>
          </div>
        </div>
      </div>
      <div class="area" v-for="(item, key) of cities" :key="key" :ref="key">
        <div class="title border-topbottom">{{key}}</div>
        <div class="item-list">
          <div class="item border-bottom" v-for="innerItem of item" :key="innerItem.id" @click="handleCityClick(innerItem.name)">{{innerItem.name}}</div>
        </div>
      </div>
    </div>
  </div>
</template>
<!--cnpm install better-scroll --save (列表拖动组件) -->
<script>
/** 引入滚动组件  Bscroll(默认阻止click事件触发) */
import Bscroll from 'better-scroll'
/** vuex的映射功能（代码优化） */
import { mapState, mapMutations } from 'vuex'
export default {
  name: 'CityList',
  /** 接收父组件传递的值 */
  props: {
    hot: Array,
    cities: Object,
    letter: String
  },
  computed: {
    /** ...展开运算符  将vuex的数据映射到计算属性computed里  将city数据映射到计算属性currentCity（此处为对象）当中 */
    ...mapState({
      currentCity: 'city'
    })
  },
  methods: {
    handleCityClick (city) {
      /** 派发一个changeCity 的action */
      /** this.$store.commit('changeCity', city) */
      this.changeCity(city)
      /** js方式页面跳转 次处为跳转到首页 */
      this.$router.push('/')
    },
    /** 将Mutation的changeCity映射到组件中changeCity的方法里 */
    ...mapMutations(['changeCity'])
  },
  /** 监听器 监听letter变化 */
  watch: {
  /** 当letter变化时触发 内容 */
    letter () {
      if (this.letter) {
        const element = this.$refs[this.letter][0]
        this.scroll.scrollToElement(element)
      }
    }
  },
  /** 生命周期函数 Bscroll 会屏蔽click函数需要 click: true 打开 */
  mounted () {
    this.scroll = new Bscroll(this.$refs.wrapper, {
      click: true
    })
  }
}
</script>
<style lang="stylus" scoped>
  @import "~styles/varibles.styl"
  .border-topbottom
    &:before
      border-color #ccc
    &:after
      border-color #ccc
  .border-bottom
    &:before
      border-color #ccc
  .list
    overflow hidden
    position absolute
    top 1.68rem
    right 0
    left 0
    bottom 0
    .title
      line-height .54rem
      background #eee
      padding-left .2rem
      font-size .26rem
    .button-list
      overflow hidden
      padding .1rem .6rem .1rem .1rem
      .button-wrapper
        float left
        width 33.33%
        .button
          margin .1rem
          padding .1rem 0
          text-align center
          border .02rem solid #ccc
          border-radius .06rem
    .item-list
      .item
        line-height .76rem
        padding-left .99rem
</style>
